Great white shark attack expert John McCosker

Three Questions For John McCosker

Published
4:00 am PST, Sunday, November 7, 2010

John McCosker, Senior Scientist at the California Academy of Sciences, presents Chronicle science reporter David Perlman with one of the sea horse figures that adorn the academy's swamp as a gift during his 90th birthday party at the California Academy of Sciences in San Francisco, Calif., on Monday, December 01, 2008. less

John McCosker, Senior Scientist at the California Academy of Sciences, presents Chronicle science reporter David Perlman with one of the sea horse figures that adorn the academy's swamp as a gift during his ... more

Photo: Laura Morton, Special To The Chronicle

Photo: Laura Morton, Special To The Chronicle

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John McCosker, Senior Scientist at the California Academy of Sciences, presents Chronicle science reporter David Perlman with one of the sea horse figures that adorn the academy's swamp as a gift during his 90th birthday party at the California Academy of Sciences in San Francisco, Calif., on Monday, December 01, 2008. less

John McCosker, Senior Scientist at the California Academy of Sciences, presents Chronicle science reporter David Perlman with one of the sea horse figures that adorn the academy's swamp as a gift during his ... more

Photo: Laura Morton, Special To The Chronicle

Great white shark attack expert John McCosker

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John McCosker, the chairman of aquatic biology at the California Academy of Sciences in San Francisco, has documented 103 great white sharks attacks on humans in California and 12 fatalities since 1952, including the death of 19-year-old Lucas Ransom, who was bodyboarding off Surf Beach in Santa Barbara County on Oct. 22 when a shark bit off his left leg. Half of California's shark attacks have occurred in the Red Triangle, from Monterey Bay out to the Farallon Islands and across to Bodega Head. McCosker spoke recently to Chronicle reporter Peter Fimrite about the ferocious ocean predators.

Q: Was the recent attack unusual in any way? Are there any great white shark attacks that stand out for you as instructive?

A: It certainly fits the pattern in terms of seasonal likelihood, and the geographic location is on the southern end of the range for white shark-human interactions in California. Several attacks have been particularly instructive. Sharks usually target the shortest kayak or surfboard when two or more are in close proximity.

Another interesting factor is that attacks within the Red Triangle are very consistent in general seasonality and location. They occur from August through October often in the vicinity of rivers entering the ocean, which are major attractants to salmon and the pinnipeds that feed upon them. The white shark mistakes us for a pinniped. "I didn't see it coming," is what most human victims said.

Q: Do great whites ever attack and eat humans simply because they are hungry?

A: Yes, however there is no direct evidence for this having occurred in California. Humans have been consumed elsewhere in the world, but there are too few examples of white shark's stomach content examinations to reach any definitive conclusions.

It is entirely possible that some Californians who were designated lost at sea may have actually been consumed, but such evidence remains unverified.

Q: Why are great whites so misunderstood? Do you think they will ever be loved and valued as much as, say, the sea otter?

A: White sharks are becoming better understood, and with that knowledge and awareness, many states and countries are protecting the species. They certainly aren't lovable as are sea otters, but the services that they provide to near shore ecosystems makes their protection imperative.